1. Technical Field
The present invention relates to a power generating system, and more particularly to a power generating system which can recover exhaust heat from a working fluid of a fluid coupling and utilize the recovered exhaust heat to generate power.
2. Background Art
There has been known a fluid coupling in which an impeller is coupled to a drive shaft (input shaft) and a runner is coupled to a driven shaft (output shaft), and power is transmitted from a driving source to a driven source through a working oil which fills a casing. The fluid coupling is employed to drive a feed pump or a blower at a variable speed in a thermal power plant, a nuclear power plant or the like, and to drive a pump or a blower at a variable speed in an ironworks or the like. When the pump or the blower is driven by the fluid coupling at a variable speed, a rotational speed of a load side, i.e. a driven machine, can be varied continuously from a minimum rotational speed to a maximum rotational speed by using a scoop tube. However, slip which is a rotational speed difference between a prime mover and a driven machine causes a slip loss.
When the rotational speed of the driven machine is low, the slip loss becomes large. Therefore, in some cases, a power loss of the fluid coupling reaches 14.8% of rated power of the driven machine at the maximum, resulting in a large energy loss.
A temperature of the working oil as a working fluid rises due to the slip loss of the fluid coupling. Therefore, the working oil discharged from the fluid coupling has been returned to the fluid coupling after being cooled down by an oil cooler. That is, heat caused by the slip loss in the fluid coupling is released outside through the oil cooler.